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How to Prep a JL for Rental Duty

Posted in How To: Tech Qa on April 27, 2018
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I won’t say I’m old, but I will say that I have been in the Jeep guide and rental business long enough to ride out the transitions between CJ, YJ, TJ, JK, and now JL. So far, other than waiting for the aftermarket to have time to develop the things we need for our typical trail use, the introduction of the JLs into our fleet has been relatively painless. As mentioned in my last article, almost every single thing that we had wished was better on the JK is better on the JLs.

What is required to make a factory Wrangler worthy of Barlow Jeep Rental status is less and less with each new generation. Barlow-worthiness is the ability to traverse the majority of the area trails without billable damage when driven by a novice to moderately experienced driver who will simply pay attention and drive slowly, with the intention to be safe and responsible. Our Jeeps are expected to traverse much of Arizona, Moab, and the Rubicon Trail, with minimal exertion.

So far, all of our test fitment is with the Rubicon model with the higher fender flares. With this, we found that a 2-inch suspension lift gives us just enough height to keep the body at what we consider a suitable height off of the ground, as well as the flexibility to run anything from 33- to 37-inch tires with full articulation. A mere 2-inch lift means we get to keep our factory driveshafts, all factory control arms except for the front lower two, and a low center of gravity. This is the simplest suspension change we have ever needed to work the 35- and 37-inch tires.

Juliet is ready for duty, wearing her 2-inch Mopar lift and 35-inch Yokohama Geolander XMTs on 17x9 Mickey Thompson wheels with 4.5-inch backspacing.

The next thing we look at is undercarriage protection. The critical things we feel are exposed to rock damage are the transmission cooler lines and the sway bar unit. It goes without saying that a crushed transmission line pretty much ends your wheeling day on the spot. We will be adding engine skidplates, which will have the pleasant side effect of also keeping the flimsy factory T-bar crossmember from crushing up into the exhaust crossover, an issue that also plagued our JKs.

Though we think the new factory metal bumpers on the JLs are sturdier than those of their Hard Rock JK predecessors, for the JLs that came with plastic bumpers, there is zero line of defense between a rock and the expensive sway bar unit. Therefore, those Jeeps will be receiving, at the very least, a sway bar skidplate up front, if not a full bumper upgrade.

Weld-on or bolt-on lower control arm skids have been standard on all generations of Barlow Jeeps since they’ve had control arms. These are very inexpensive ways to insure that control arms stay attached to the axlehousing. Moving to the back, this new generation of Dana 44 rear has a thin 1/2-inch lip hanging down in harm’s way. We’ll add a heavy-duty diff cover to those to prevent peeling back the cover or cracking the housing.

We heard that 35-inch tires fit on the Rubicon’s high fenders with no lift. We found this to be untrue with 35-inch tires at full articulation.

Finally, we throw on some heavier-duty tires in the tread of our choice. Note that the factory wheels must be upgraded to aftermarket offset wheels in order to run 35- or 37-inch tires for full articulation and steering without rubbing the front shocks. And though the factory spare tire carrier on the Rubicon fits a 35-inch tire, we are adding the tailgate reinforcement to all of our units—37-inch tires will require a tire carrier bracket or other modification. We also reprogram so that speedometer and shift points are correct for tire size.

And that’s it. Really. Looking back on what it took to fit 35s on TJs, we keep thinking we must be missing something. Modifying the Wrangler has never been easier.

We were hoping to be able to use the cool factory wheels with 35-inch tires, but found that at articulation and steering lock, they rub on the front shocks. So, with 35-inch tires or bigger, you need a wheel with less backspacing than factory. We use 4.5- to 4.75-inch backspacing on 17x8.5 wheels for good clearance.
Yes, the Mopar 2-inch lift fits 37-inch tires, with only minor rubbing in the rear at full articulation. We can live with that!
The 37-inch Falken WildPeak M/T on a 17x9 Pro Comp wheel at full stuff with the 2-inch Mopar lift. If the slight rubbing on the plastic behind the wheel bothers you, it can be removed with four bolts.
We don’t like the obvious strain that 35- and 37-inch tires put on the magnesium tailgates, so we are installing reinforcements on all of our rentals.
I don’t want to risk nicking those transmission cooler lines on a rock. We also know that the factory T-bar crossmember below the exhaust crossover will not survive long. An aftermarket engine skid will solve both.
Photo: Rock Hard 4x4
Compare this nicely protected engine and transmission, gas tank, and transfer case with the previous factory photo. Which would you rather take on the trail?
The new Dana 44s on the JLs are better in every way, except for this skinny exposed lip on the rear diff. We are currently working with Next Venture Motorsports to develop a heavy-duty diff cover and full diff guard to prevent what we see as a cracked housing risk.

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